1. Field of the Invention
The present invention relates to an inkjet ink composition and an inkjet recording method.
2. Description of the Related Art
In recent years, along with the spread of computers, inkjet printers have been widely used not only in offices but also in homes for printing characters and images on paper sheets, films, fabrics, and so on.
Inkjet recording methods include a method of using a piezoelectric element to eject droplets under pressure, a method of thermally generating bubbles in ink to eject droplets, a method of using an ultrasonic wave, and a method of using an electrostatic force to suck and eject droplets. Examples of ink for use in such inkjet recording include water-based ink, oil-based ink and solid (fusible) ink. Among these types of ink, water-based ink is predominant for current inkjet recording, because it is relatively superior to oil-based ink and solid (fusible) ink in terms of the ability to simultaneously satisfy the requirements for production, handling, odor, safety, and so on.
Dyes for use in such inkjet recording ink are required to have: high solubility in a solvent (ink medium); the ability to provide high-density recording; good hue; high fastness to light, heat, air, water, and chemicals; the ability to provide good fixation on image-receiving materials with less blurring; high storability of ink; no toxicity; high purity; and availability at low cost.
Concerning means for solving the problems with ozone resistance and ejecting stability, Japanese Patent Application Laid-Open (JP-A) No. 2007-204632 discloses an ink composition including 10% by weight to 80% by weight of a compound having a thioether or sulfoxide moiety, a specific magenta dye, and a water-soluble organic solvent.